Per Inge Oestmoen, Intervention by the KGB does answer the key questions.
Why did the hikers exit the tent so hurriedly and so under clothed? They were forced out at gunpoint.
How did the severe injuries to several hikers occur? They were beaten by rifle stocks. Interestingly, those beaten were Zolotaryov, WWII veteran and probably the one most knowledgeable about hand-to-hand combat; Zolotaryov's friend, Thibeaux-Brignolle; and Dubinina, who, upon reading the various diaries, seems to have a formidable temper.
Was there a cover-up during the investigation? If the KGB was involved, there certainly would be a cover-up.
Why has no substantial evidence ever come to light since? In 1959, the new head of the Communist Party, Khrushchev, could not in any way be implicated in the incident. In 2024, the Russian government, would not want such an embarrassment on its hands.
Of course, intervention by the KGB raises countless questions, also. Then again, without indisputable evidence, every theory raises as many questions as it answers.